Who Am I? Secure Identity Registration on Distributed Ledgers Sarah - - PowerPoint PPT Presentation

▶
who am i secure identity registration on distributed
SMART_READER_LITE
LIVE PREVIEW

Who Am I? Secure Identity Registration on Distributed Ledgers Sarah - - PowerPoint PPT Presentation

Jul 07, 2023 281 likes •719 views

Who Am I? Secure Identity Registration on Distributed Ledgers Sarah Azouvi Mustafa Al-Bassam Sarah Meiklejohn (University College London) 1 Cryptocurrencies 2 Cryptocurrencies Pseudonyms 2 Cryptocurrencies Pseudonyms tx(pk A pk B ) 2

slide-1
SLIDE 1

Who Am I? Secure Identity Registration on Distributed Ledgers

Sarah Azouvi Mustafa Al-Bassam Sarah Meiklejohn (University College London)

1

slide-2
SLIDE 2

Cryptocurrencies

2

slide-3
SLIDE 3

Cryptocurrencies

2

Pseudonyms

slide-4
SLIDE 4

Cryptocurrencies

tx(pkA pkB)

2

Pseudonyms

slide-5
SLIDE 5

Blockchain for distributing benefits?

3

slide-6
SLIDE 6

Blockchain for distributing benefits?

3

slide-7
SLIDE 7

Blockchain for distributing benefits?

3

slide-8
SLIDE 8

Related

slide-9
SLIDE 9

PKI

Related

slide-10
SLIDE 10

PKI Anonymous Credentials

Related

slide-11
SLIDE 11

PKI Anonymous Credentials Identity management on Blockchains

Related

slide-12
SLIDE 12

PKI Anonymous Credentials Identity management on Blockchains

Related

slide-13
SLIDE 13

PKI Anonymous Credentials Identity management on Blockchains

Related

slide-14
SLIDE 14

PKI Anonymous Credentials Identity management on Blockchains

Related

slide-15
SLIDE 15

PKI Anonymous Credentials Identity management on Blockchains

uPort

Related

slide-16
SLIDE 16

PKI Anonymous Credentials Identity management on Blockchains

uPort ChainAnchor

Related

slide-17
SLIDE 17

PKI Anonymous Credentials Identity management on Blockchains

uPort MIT Digital certificates ChainAnchor

Related

slide-18
SLIDE 18

Security

Registration I’m Alice pk

5

pk Verification

slide-19
SLIDE 19

6

Security

I’m Alice pk pk

6

Registration Verification

slide-20
SLIDE 20

6

Security

I’m Alice pk pk

6

Registration Verification

slide-21
SLIDE 21

7

Security

I’m Alice pk pk

7

Passive verification

7

slide-22
SLIDE 22

8

Security

I’m Alice pk pk

8

Active verification

8

slide-23
SLIDE 23

9

Security

I’m Alice pk pk

9

Attribute integrity

9

slide-24
SLIDE 24

9

Security

I’m Alice pk pk

9

Attribute integrity

9

slide-25
SLIDE 25

9

Security

I’m Alice pk pk

9

Attribute integrity

9

pk

slide-26
SLIDE 26

9

Security

I’m Alice pk pk

9

Attribute integrity

9

pk

slide-27
SLIDE 27

10

I’m Alice ? pk

Security

Attribute privacy

slide-28
SLIDE 28

Our constructions

11

slide-29
SLIDE 29

Web of trust

12

Registration I’m Alice, my public key is pk tx{pkR (pk,pkrev)}

slide-30
SLIDE 30

13

Web of trust

Registration I’m Alice, my public key is pk tx{(pkR1,…,pkRn) (pk,pkrev1,…,pkrevn)}

13

slide-31
SLIDE 31

13

Web of trust

Registration I’m Alice, my public key is pk tx{(pkR1,…,pkRn) (pk,pkrev1,…,pkrevn)} Verification tx? pkrev?

13

slide-32
SLIDE 32

Web of trust

14

  • Verification: passive (on the blockchain)
  • Attribute integrity: partially. Registrars cannot impersonate Alice.

But malicious coalition of users can collude

  • Privacy: no

Alice + pk

slide-33
SLIDE 33

Web of trust

14

  • Verification: passive (on the blockchain)
  • Attribute integrity: partially. Registrars cannot impersonate Alice.

But malicious coalition of users can collude

  • Privacy: no

Alice + pk

slide-34
SLIDE 34

Blinded web of trust

  • Verification: active
  • Attribute Integrity: partially
  • Privacy: yes

15

slide-35
SLIDE 35

Casascius

16

pk1 sk1, pk1 sk2 sk2 pk2=pk1sk2 pk2=pk1sk2 =gsk1.sk2

slide-36
SLIDE 36

17

Multi-Casascius

17 17

slide-37
SLIDE 37

18

Multi-Casascius

18

slide-38
SLIDE 38

Multi-Casascius

  • Verification: Passive
  • Attribute Integrity: Satisfied. First registrar verifies id. No

registrar knows the private key.

  • Privacy: yes. As long as one registrar honest

19

slide-39
SLIDE 39

Implementation

20

https://github.com/musalbas/trustery

slide-40
SLIDE 40

Implementation

  • Add attribute (different types)
  • Sign attribute
  • Add/Sign Blind attribute

21

slide-41
SLIDE 41

Implementation

22

slide-42
SLIDE 42

Conclusion

  • Different methods for achieving

registration in public distributed ledgers

  • Light-weight crypto primitives
  • Open problem: key recovery

23

slide-43
SLIDE 43

Questions?

24